APS News


Zero Tolerence for "Zero Gravity"
The answer given to the second limerick listed in the Zero Gravity section of APS News in the Aug/Sept 1998 issue is arguably incorrect and libelous [Answer: Gwen has forty-two boyfriends. 42-1=41. 41+3=44. 44/4=11. 11-1=10.]. A better answer, in my opinion, is that Gwen has only nine boyfriends, rather than 42. The key lies in the interpretation of the words "Together give", which I take to mean the operation of addition of the two preceding phrases separated by the word "and". Thus "one less" (9-1=8) "and three more divided by four" ((9+3)/4=3), "Together give" (8+3=11) "one more than ten" (11). I fear, though, that it is too late to save Gwen's sullied reputation.
Kevin Gahagan

Los Alamos National Laboratory

I note that in Item 5 of Zero Gravity in the July 1998 issue of APS News, the force that prevents an insect from going through normal matter is said to be the electrostatic repulsion between the charged particles making up the atoms in the two bodies. I have always thought that the electrostatic forces between the electrons and nuclei of two atoms pretty much cancel one another out, and what is left is a very weak attractive force usually associated with the name of van der Waals. The fact that two atoms do not penetrate each other, I thought, was a consequence of the Pauli principle: the electrons of one atom cannot get into the filled shells of the other atom. But perhaps the laws of physics are different in Zero Gravity if so, this should please NASA no end.
Groebenzell, Germany

Renormalization of Bloopers
I read the July Zero Gravity ''Top Ten Star Trek Bloopers,'' by Lawrence Krauss, with some anxiety: Were the bloopers all supposed to have been in the show? To avoid ambiguity, I have included a second-order correction below in which each blooper has been categorized either as "correct fiction" or "incorrect fiction". Readers also may choose the category into which their other theories best might fall.

1. In Space, No One Can Hear You Scream. Correct Fiction. Also, nothing really "blows up" in space either: There isn't any air to transmit pressure differences.

2. Faster Than A Speeding Phaser. Incorrect Fiction. Any such weapon must be aimed; the aiming action might be observed and the beam thus avoided. Also, some of the initial beam might be observed at the target before the deadly part arrived, allowing the latter to be avoided.

3. If the Plot Isn't Cracked, Maybe the Event Horizon Is. Incorrect Fiction. An event horizon MIGHT not be smooth and symmetrical, allowing it to appear "cracked."

4. How Solid a Guy Is the Doctor? Correct Fiction. A hologram image can't be magnetically confined. However, a hologram might be so confined. Also, spin would allow uncharged particles to interact with a magnetic field (weakly).

5. To InterPhase or Not To InterPhase. Probably Correct Fiction, but seems to have a bug.

6. Sweeping Out the Baby With the Bath Water. Same as 5: Sweeping the baryons off the Enterprise might just leave it shinier (if not all were removed).

7. How Cold is Cold? Correct Fiction: Can't get to -295 degrees Celsius.

8. I Have Seen the Light. Incorrect Fiction. Space IS filled with dust, as the astronauts servicing the Hubble found to their dismay. Also, dense enough energy might cavitate the vacuum enough to make the beam visible in all directions.

9. Astronomers Get Picky. Incorrect Fiction. Yes, a geosynchronously orbiting vehicle would remain stationary relative to any point on the equator (ignoring secular corrections). However, seen in a perspective other than from a point through a diameter of the planet and through the vehicle, the vehicle WOULD appear to move against the planet's surface.

10. Those Darned Neutrinos. Incorrect Fiction. For a vehicle by assumption able to exceed the speed of neutrinos, passing a neutrino in flight would make it RIGHT-handed. This is the "symmetry-breaking" referred to in theories that allow the neutrino to be massive (and thus be passed by a beam of light).

John Michael Williams
Redwood City, CA

The High Cost of Tenure
The June 1998 Back Page ''Keep Tenure: Fix the Problems'' by Frank Franz is clear and obviously from an expert. However, has anybody considered the cost of the proposed annual reviews? Just to remove a few (1% ?) incompetent (or inadequate) tenured professors, 100% of them (and their staff) have to spend hours and hours each year to pass such annual reviews if they are done properly. Just another way to increase bureaucracy and with it overhead.
M. Drosg
University of Vienna

Why God Never Got Tenure
I very much enjoyed the April 1998 Zero Gravity column but I have one very serious criticism: the title should be "Why God Never Got Tenure," rather than a PhD. The criteria cited are not particularly pertinent to obtaining a doctorate, but are among the reasons cited for denying tenure.
Leo Silber
Brooklyn, NY

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Editor: Barrett H. Ripin